Bacon forming system and apparatus



April 20, 1965 T. E. cHRlsTENsEN BACON FORMING SYSTEM AND APPARATUSFiled May 31. 1963 INVENTOR. THOR E. CHRISTENSEN ATIORNEY United StatesPatent O 3,179,039 BACON FRMJNG SYSTEM AND APPARATUS Thor E.Christensen, Maywood, Ill., assigner to Chernetron Corporation, Chicago,Ill., a corporation of Delaware Filed May 31, 1963, Ser. No. 284,428 11Claims. (Cl. 100-42) The present invention relates to a bacon formingsystem and apparatus, and more particularly to an improved system andapparatus for forming bacon to minimize the problem of wrinkles inpressed bacon slabs.

Bacon slabs are generally formed in a bacon press into substantiallyrectangular shape so that bacon slices of approximately uniform lengthand width can be obtained from the bacon slab. During the pressingoperation the Width of the bacon may be reduced from about l2" to about9". However, due to the fact that an unpressed bacon siab has adepression o-r cavity in its inside surface at the ham end, called aiiank pocket, wrinkling will occur in the fat side of bacon slabs at theilank pocket during the pressing operation due to launching-up of thethinner section material at the flank pocket. This wrinkled condition ofa portion of the bacon slab results in a yield of misshapen and raggedslices of bacon from the wrinkled portion of the slab which have to bedowngraded to a lower quality level, resulting in a lower selling pricefor that portion of the sliced bacon.

It has been proposed that a bacon forming press be provided with ashaped solid metal filler plate which has a smooth rounded surface andwhich is shaped and sized to approximately fill an average flank pocketduring the pressing operation. However, in commercial meat processingoperations substantial wrinkling may still occur in the pressed slabs inspite of the use of the solid metal ller plate. Specically, experiencehas shown that the incompressible solid metal plate causes a largeWrinkle or wrinkles to be permanently pressed into the rather easilydeformable bacon slab by the pressure applied to it during the pressingoperation. Moreover, as a metal filler plate necessarily has a specicsize and shape, and as the bacon slabs being processed obviously haveirregular shapes and surfaces including flank pockets of different sizesand shapes, it is not always possible to even approximately obtain adesired size relationship between the plate and the flank pocket,resulting in objectionable variations in the pressed bacon slab product.Although the prior art proposes that there be different locations of thefiller plate to accommodate bacon slabs of different sizes,nevertheless, this has not worked out in practice because of theobviously substantial amount of time required to separate unpressedbacon slabs into lots having flank lpockets of like size, and then torelocate the filler plate each time a different lot is processed.Moreover, the prior art solid metal liller plate has been employed toenter the ank pocket from the lean side of the bacon. In practice thishas been found to be unsatisfactory because of objectionable depressionor cavity will then be pressed into the lean edge of the bacon which isthe only portion of the sliced bacon visible through the window providedin the usual bacon package.

It is therefore a primary object of the present invention to provideimproved structure for eliminating the wrinkling that occurs in pressingbacon slabs.

Another object of the invention is to provide an improved bacon formingsystem and apparatus for yieldingly supporting a certain portion of thebacon slab during the pressing operation to eliminate wrinkles in thepressed slab.

A further object is to provide improved bacon pressing structure adaptedto accommodate bacon slabs with flank pockets of any size and shape, andturn out rectangular substantially wrinkle-free pressed slabs.

Still another object is to provide an improved method for pressing baconslabs such that wrinkling during the pressing operation is held to aminimum.

A further object is to provide a method for pressing bacon slabs toobtain the maximum yield of high quality bacon including a step ofproviding yielding pressure at a selected portion of the bacon slab.

Briefly stated, in accord with the preferred illustrated embodiment ofthe present invention, there is provided a bacon press having a wallmember consisting of a liexible diaphragm or pad of rubber-like materialiiush mounted in a plate of the press, for providing yielding supportfor a cavitied portion of the unpressed bacon slab. The rubber-likediaphragm wall member is disposed over means for expanding it includingthe outlet of a fluid line for conducting a fluid under pressure to theinside of the diaphragm. The bacon slab to be pressed is disposed withits flank pocket portion directly over the diaphragm yielding supportmeans with the fat side of the bacon being disposed against thediaphragm. After the press controls are actuated to cause closing of thepress at a predetermined desired spacing between the top platen and thebottom plate of the press a limit switch is actuated controlling asolenoid operated valve in the iluid line, a compressed air line in theillustrated embodiment. The air valve opens, releasing high pressure airbehind the diaphragm, causing it to expand or inflate and press againstthe fat side of the bacon belly directly opposite the Hank pocketportion. As the pad is resilient and deformable, it yieldingly supportsthe adjacent portion of the bacon belly during the pressing operation.Closing of the press with the yielding support provided by the iniiateddiaphragm causes the plastic and deformable bacon to tend to fill theHank pocket cavity regardless of its size and shape, resulting in asubstantially uniform cross section in Iall portions of the finishedbacon slab. Moreover, as the lean side of the bacon is contacted by aliat and rigid press plate, the lean top edge of the bacon exposed tothe customers view through the bacon package window is substantiallystraight and free of objectional voids or depressions. As no substantialWrinkling of the bacon slab can occur during the pressing operation, itcan be further processed to provide uniform bacon slices and a maximumyield of high quality bacon.

The invention both as to its organization and method of operation,together with further objects and advantages will best be understood byreference to the following description taken in connection with theaccompanying drawing in which:

FIG. l is a fragmentary perspective view of a bacon forming press of atype in which the present invention can advantageously be employed;

FIG. 2 is a plan View of the bottom or base plate of the bacon formingchamber in the bacon press of FIG. l;

FIG. 3 is a cross section view of an unpressed bacon slab taken throughthe flank pocket, and showing the bacon slab superimposed on the platestructure of FIG. 2 in pressing position;

FIG. 4 is a sectional view of the bacon forming chamber of the baconpress of FIG. l taken approximately along the line 4 4 of FIG. 1 showingthe iniiatable diaphragm and the associated fluid line and with a baconslab in the forming chamber and the top platen pressing on the baconslab;

FIG. 5 is a perspective View, partially broken away, showing details ofthe diaphragm of FIGS. l-4.

FIG. 6 is a schematic view illustrating the electric and duid linesemployed in the operation of the invention;

FIG. 7 is a fragmentary plan view of a bottom or base plate of a baconpress provided with a resilient shaped fiiler pad modiication of theinvention; and

FIG. 8 is a sectional view of the resilient shaped iller pad of FlG. 7taken along the line S- Referring now to the drawing, and particularlyto FIG. 1, there is shown a bacon forming press 19 of the type having abacon forming chamber 11 therein provided by reiatively movablepressi-ng plates including a bottom plate or platen 12, a top plate ofplaten 13, end plates 14 and 15, and side plates 16 and 17. All of thesepressing plates have fiat, rigid and smooth surfaces and are aligned soas to produce a rectangular shape bacon slab. The length and thicknessof the finished bacon slab will vary depending on the dimensions of theoriginal bacon belly and the pressure used during the pressingoperation, and the width of the slab will depend on the setting of asuitable width gauge 9 set by the operator. The press 10 ishydraulically operated, and top platen 13, end plate 15, and side plate17 are hydraulically operated movable plates which operate in sequenceby means of suitable conventional control valves, the details of whichare omitted for brevity. Side or front plate 17 is of the disappearingtype, arranged to drop down out ot sight at the conclusion of thepressing operation to facilitate loading and unloading of the formingchamber 11. The press 1@ includes means for moving the movable pressplates to carry out a bacon pressing operation including a conventionalhydraulic iiuid pump (not shown) driven by a conventional electric motor(not shown), energized from a suitable power source such as a 110 voltsupply line, actuated by a push button start-stop switch 18.

The invention to which this application is directed is seen most clearlyin FIGS. 2, 3, 4, 5, and 6. It includes means providing yielding supportfor the cavitied Hank pocket portion of the bacon comprising arectangular diaphragm 3@ of a flexible resilient material, which mayadvantageously be of a suitable grade of polyurethane or neoprene, liushmounted in plate 12 over the outlet of a high pressure air li-ne 31.Diaphragm 34B may simply be mounted in a cavity formed in the top ofplate 12 or the mounting for diaphragm 3d may include an opentoppedkrectangular box 29 recessed in plate 12, and formed by a base member 29aand side members 29b. The base member 29a has a hole Stia through it,adapted to accommodate a fitting 31a connecting to line 31. Thediaphragm 36 may preferably include an embedded rectangular metal plate38 (see FIGS. 3-6) for maintaining its shape. Plate 38 has a titting 38a(FIGS. 5 and 6) mounted in a central opening in plate 3S, adapted forconnection to fitting 31a. The diaphragm Si) is bonded only to thebottom surface and the sides of plate 38, thus forming a shallowenclosed space 3tlb (FIG. 6) communicating with line 31 via fittings 38aand 31a, which enlarges on inflation of Ydiaphragm 311 (FIG. 4). The airline .31 may be supplied from a conventional supply of compressed air32, connected in turn to a line 33 which may advantageously include aconventional ilter 34, and a regulator 35 provided with an adjustingscrew and handle 36 for adjusting the pressure used to inate thediaphragm Sil. The flow of high pressure air to the diaphragm 3d iscontrolled by means including a solenoid operated valve 37. The solenoidassociated with valve 37 is energized from a suitable power supply whichmay advantageously be that provided for the motor and other circuitry ofthe press 10.

Prior to pressing, the bacon slabs to be pressed are cooled byconventional means to a predetermined temperature suitable for baconforming operations. A temperature of about 25 F. in the bacon slabs hasbeen found to yield good forming results, as the bacon slab is somewhatplastic and deformable at this temperature and when subjected to thepressing operation will take a set which does not materially changeafter the pressing operation.

The press 1t) is prepared for pressing operations by actuatingstart-stop switch 18. An unpressed bacon slab 411 (see FIG. 3), havingirregular surface and varying contours including a tiank pocket orcavity 41 in the lean top 42 of bacon slab 40 at its ham end, is thenplaced in the chamber 11 of press 10. A fat bottom of the bacon slab 40is indicated at d2. The sequence of the pressing operations of the press1t) is initiated by the dualcontrol levers 20 and 21, which for safetyreasons, are arranged so that both hands of the operator must bepressing downward on the levers 2t) and 21 in order to operate a bar 2da(FIG. 1) which must be depressed to start and carry out the cycle. Afterthe levers 20 and 21 are pressed downward to operate bar 2da, bar 20aactuates a hydraulic valve 19 (FIG. l) to start the press cycle. A limitswitch 50 (FIGS. 1 and 6) is also actuated to close condition by theposition of the levers 20 and 21, thus setting up a circuit to energizethe solenoid of valve 37 (FG. 6). The disappearing bar 17 (FIG. 1) thenrises through th-e operation of the control valves controlling the cycleof press 1d to define the bacon forming chamber 11. Next top platen 13moves downward relative to bottom plate 12. When the platen 13 islowered to a predetermined relative spacing between plates 12 and 13assuring application of some pressure on the bacon slab 40, the presscross-member carrying platen 13 actuates a limit switch 51 (FIGS. 1 and6), which may advantageously be mounted on a slotted bracket fastened tothe top of press 10 (FIG. 1), causing the energization of solenoidoperated valve 37. It should be noted that limit switch 51 thusconstitutes means for actuating expansion of diaphragm 3i?, responsiveto sensing of a desired spacing between plates 12 and 13 and therebyprovides means preventing inflation of diaphragm 3@ until there ispressure on the bacon slab :trom top platen 13. This prevents diaphragm311 from being accidentally blown out of its mounting when thecompressed air valve 37 is opened. It should also be noted that thelimit switchesStl and 51 may advantageously be adjustably mounted sothat they may be precisely located for actuation at desired portions ofthe press cycle.

Energization of the solenoid causes valve 37 to open, releasing highpressure air through line 31 to inflate the diaphragm 36, therefore,expands concurrently with application of pressure to the bacon slab,forcing the bacon slab at the Hank pocket zone or portion 41 against thepress top platen 13 (see FIG. 4). Side plate 1o is then actuated topress inward against the bacon slab. When plate 16 has advanced to apredetermined point set by width gauge 9, cam means, not shown, controlthe operation of press 10 to actuate an end cylinder 15a to press theends of the bacon. During all of these pressing movements of the liatand irm or rigid press plates 12, 13, 14, 15, 16 and 17, the yieldingdiaphragm 39 is exerting a yielding pressure against the iank pocketportion 41 of the bacon slab opposite the flank pocket in the lean sideof the bacon slab (see FIG. 4). When the pressing cycle is completed,the levers 20 and 21 are released, permitting the cylinders of press 10to retract, and at the same time limit switch 5d opens (FIGS. 1 and 6)breaking the circuit energizing the solenoid of Valve 37. This allowsthe diaphragm 30 to deiiate before upper platen 13 leaves the bacon.

The press 10 is adjusted by turning a valve adjustment handle 71 formingpart of a relief valve 'iti (FIG. l) so that during pressing operationsthe iiat and irm pressing plates 1217 apply pressure against the top,bottom, sides and ends of the bacon slab 46 such as to develop apressure of approximately pounds per square inch in the bacon asindicated by a gauge 5S (FIG. 1). In the improved method disclosedherein it has been found that the lair pressure exerted against thediaphragm 30 may advantageously :be adjusted by regulator screw 36 toapproximately 50 pounds per square inch as indicated by gauge 56. As thecooled unpressed bacon slab is somewhat plastic and deforma-ble at itsapproximately 25 F. temperature during the pressing operation, thedilerence in pressure developed in the bacon by the flat plates 12, 13,14, 15, 16, and 17, over that exerted by the diaphragm results in apreferential formation of the bacon slab in directions away from thehigh pressures applied by the flat plates toward the cavity at'the ankpocket. Therefore, during the forming operation the bacon slab throughthe operation of the present invention is reshaped so that material fromthicker portions of the unpressed bacon slab shifts somewhat in thedirection of the thinner ilank pocket portions, resulting in asubstantially uniform crosssection in the finished bacon slab.

Tests based on actual commercial lots in a large bacon producers plantemploying the preferred embodiment of the invention indicate that thepresent invention substantially eliminates the wrinkling problem inpressing bacon slabs and achieves a marked improvement in the yield ofhigher quality bacon from a bacon slab.

Referring now to FIGS. 7 and 8, there is shown therein a modification ofthe invention in which a press plate wall member consisting of aresilient shaped pad 60 of a suitable rubber or rubber-like material isemployed in place of the expandable diaphragm 30. The pad 60 is shapedand sized approximately in accord with the flank pocket of a typicalunpressed bacon slab as indicated in FIGS. 7 and 8, and may be suitablybonded to a mounting plate 61. The mounting plate 61 may be secured to apress bottom forming plate 65 by any suitable means, for example, aplurality of mounting screws 62. In utilizing the embodiment shown inFIGS. 7 and 8 an unpressed bacon slab is placed on the bottom formingplate 65 of a conventional bacon forming press with the fat side of thebacon belly against the pad 6i). The flank pocket portion of the baconbelly is disposed directly over the pad 60. During pressing operationsthe pad 60 provides a resilient yielding pressing member which operateson the bacon slab in conjunction with the flat plates of the press thusproviding yielding support of the bacon slab at the flank pocket portionduring pressing, and which thereby permits the bacon slab to be reshapedto the desired wrinkle-free rectangular shape during the formationoperation.

Compressed air is used for the fluid to iniiate or eX- pand thediaphragm 30 in the illustrated embodiment of FIGS. 1-6. However, itwill be recognized that other fluids might also be suitable, forexample, another gas, or a suitable hydraulic fluid.

While it is more convenient to mount the resilient wall member 30 (or60) in the bottom plate of the press, with suitable -modications itcould also be mounted in the top platen of a press, in which case thebacon slab would be inserted in the forming chamber with the fat side upand the flank pocket portion open downwardly.

While there has been described what is at present considered to be thepreferred embodiments of the invention, it will be understood that othermodifications may be made therein and are intended to be included withinthe scope ofthe appended claims wherein there is claimed:

l. Method of forming bacon slabs having flank pockets into substantiallywrinkle-free rectangular slabs, comprising the steps of placing anunpressed slab on a fiat press surface, restraining movement of saidunpressed slab at one side and on one end, and pressing the slab fromthe top and from the unrestrained side and end thereof but concurrentlyyieldingly supporting the flank pocket portion of the bacon slab.

2. Method of pressing .a bacon slab having a flank pocket into asubstantially rectangular shape in a bacon press, comprising the 4stepsof: cooling a bacon slab to a desired forming temperature of about 25F., placing the bacon slab in a forming press cavity, limiting expansionof said slab at its sides and on one end, and pressing the slab from thetop, one side and from the unrestrained end thereof but yieldinglysupporting the flank pocket portion of the bacon slab, whereby the baconslab may be formed into a substantially rectangular shape with 6 aminimum formation of wrinkles at the dank pocket portion.

3. Method of pressing a bacon slab having a flank pocket portion,comprising steps of: applying pressure against the top, bottom, sidesand ends of a bacon slab to press the bacon slab into a substantiallyrectangular shape but yieldingly supporting the bacon slab at its flankpocket portion, so that the pressed bacon slab is substantiallywrinkle-free at its flank pocket portion.

4. Method of pressing a bacon slab having a flank pocket portion into asubstantially wrinkle-free rectangular shape, comprising the steps of:applying pressure against the top, bottom, sides -and ends of a baconslab to press the bacon slab into a substantially rectangular shape butyieldably supporting the bacon slab at the iiank pocket portion with alesser pressure so that there will be preferential forming of the baconslab in directions leading toward the iiank pocket portion withconsequent filling of the flank pocket portion Without substantiallywrinkling the flank pocket portion.

5. Method of pressing a bacon slab having a lean top and a fat bottominto a substantially wrinkle-free rectangular shape, comprising thesteps of: applying pressure against the top, bottom, sides and ends of abacon slab to press the bacon slab into a substantially rectangularshape but yieldably supporting the bacon slab opposite the liank pocketat the flat bottom so that there will be preferential forming of thebacon slab in directions leading toward the iiank pocket portion withconsequent filling of the iiank pocket portion without substantiallywrinkling the iiank pocket portion.

6. In a press for pressing bacon slabs having flank pocket portions: apair of relatively lmovable, at, rigid platens for contacting andexerting pressure against the top and bottom of a bacon slab, a pair ofat, rigid, side plates and a pair, of flat, rigid end plates forexerting pressure respectively against the sides and ends of the baconslab, and means disposed at the surface of one of said platens forexerting yielding pressure against the bacon slab at its ank pocketportion, so that as the bacon slab is pressed by said platens and saidside and end plates, said means yields to enable said slab to be formedinto a substantially wrinkle-free rectangular shape.

7. In a press for pressing bacon slabs having flank pocket portions: a-p-air of relatively movable, fiat, rigid platens for contacting andexerting pressure against the top and bottom of a bacon slab, a pair offlat, rigid side plates and a pair of flat, rigid end plates forexerting pressure respectively against the sides and ends of the baconslab, and means providing yielding support for the bacon slab at itsflank pocket portion, said means including an expandable diaphra-gmmounted by one of said pl-atens, so that said bacon slab can beyieldably supported at its flank pocket portion While said platens andsaid side and end plates exert pressure against said bacon slab.

8. In a press for pressing bacon slabs having flank pocket portions: apair of relatively movable, flat, rigid platens for contacting andexerting pressure against the top and bottom of a bacon slab, a pair offlat, rigid side plates and a pair of flat, rigid end plates forexerting pressure respectively against the sides and ends of the baconslab, means providing yielding support for the bacon slab at its ankpocket portion, said means including an expandable diaphragm mounted byone of said platens, means to deliver a iiuid under pressure against theunderside of said diaphragm for expanding said diaphragm, and meansoperable when said platens are moved to a predetermined spacing fromeach other `for operating said expanding means.

9. In :a press for pressing bacon slabs having flank pocket portions: apair of relatively movable, at, rigid pl-atens for contacting andexerting pressure against the top and bottom of a bacon slab, a pair ofhat, rigid side plates and -a pair of iiat, rigid end plates forexerting pressure respectively against the sides and ends of the baconslab, an expandable diaphragm mounted by one of said platens yforengagement with a bacon slab at its flank pocket portion, means todeliver a fluid under pressure to the underside of the diaphragm -forexpanding said diaphragm, and means for regulating the uid pressureacting against said diaphragm so that as pressure is applied to thebacon slab by said platens `and said side and end plates, the flankpocket portion is yieldably supported by said diaphragm which yields asthe pressure in the bacon slab increases.

10. In a press for pressing bacon slabs having anlc pocket portions: apair of relatively movable, flat, rigid platens for contacting andexerting pressure against the top and bottom of a bacon slab, Aa pair offlat, rigid side plates and a pair of at, rigid end plates for exertingpressure respectively against the sides and ends of the bacon slab, anexpandable diaphragm flush mounted in one of said platens, and means toexpanding said diaphragm for providing yielding support against a flankpocket portion of the bacon slab.

11. In a press for pressing bacon slabs having flank pocket portions: apair of relatively movable, flat, rigid platens for contacting andexerting pressure against the top and bottom of a bacon slab, a pair ofat, rigid side plates and a pair of at, rigid end plates for exertingpressure respectively against the sides and ends ofthe bacon slab, and apad composed of a resilient material mounted by one of said platens, sothat said bacon slab can be yieldably supported at its Hank pocketportion While said platens and said side and end plates exert pressureagainst said bacon slab. l

Reiter-ences Cited by the Examiner UNlTED STATES PATENTS 1,891,344 12/32Casse 10Q-211 X 2,043,366 6/36 Bech 10G-232 2,066,085 12/36 Whistler.

2,229,862 1/41 Menges 10G-232 2,363,107 11/44 Young.

2,519,661 8/50 Johnson V100---295 X 2,762,296 9/56 Dunnegan 10G- 295 X3,055,760 9/62 Morrison 99-194 WALTER A. SCHEEL, Primary Examiner.

1. METHOD FO FORMING BACON SLABS HAVING FLANK POCKETS INTO SUBSTANTIALLYWRINKLE-FREE RECTANGULAR SLABS, COMPRISING THE STEPS OF PLACING ANUNPRESSED SLAB ON A FLAT PRESS SURFACE, RESTRAINING MOVEMENT OF SAIDUNPRESSED SLAT AT ONE SIDE AND ON ONE END, AND PRESSING THE SLAB FROMTHE TOP AND FROM THE UNRESTRAINED SIDE AND END THEREOF BUT CONCURRENTLYYIELDABLY SUPPORTING THE FLANK POCKET PORTION OF THE BACON SLAB.